scholarly journals Antibacterial activity of lupeol from the bark of Dehaasia cuneate (Lauraceae)

2021 ◽  
Vol 2 (2) ◽  
pp. 145-148
Author(s):  
Andi Rifki Rosandy ◽  
◽  
Sumail Sidik Ode Ishak ◽  
Noor Aziiraa Sabri ◽  
Wan Yaacob Wan Ahmad ◽  
...  

Dehaasia is a member Lauraceae. It is locally known as ‘gajus hutan’ or ‘pekan’. A triterpenoid, lupeol was isolated from the bark of Dehaasia cuneate. The structure of the isolated compound was determined using spectroscopic methods, such as UV–vis, FT-IR, 1D and 2D NMR, and mass spectrometer. The isolated compound was tested against Gram-negative and positive bacteria using agar disc diffusion technique. The results showed that lupeol had a moderate inhibition zone value of 10.0±0.00 mm against Gram-negative Serratia marcescens ATCC 14756 whereas low inhibition which is 7.0±0.00 mm against Escherichia coli ATCC 25922, Vibrio fluvialis ATCC 33809, Bacillus subtilis ATCC 6633, and Methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300.

2015 ◽  
Vol 761 ◽  
pp. 402-406 ◽  
Author(s):  
Siti Aishah Mohd Hanim ◽  
Nik Ahmad Nizam Nik Malek ◽  
Zaharah Ibrahim ◽  
Mashitah Mad Salim ◽  
Nur Isti'anah Ramli ◽  
...  

The antibacterial activity of functionalized zeolite NaY (CBV100) with different concentrations of 3-aminopropyltriethoxysilane (APTES) (0.01, 0.05, 0.20 and 0.40 M) was studied against Staphylococcus aureus ATCC 6538 (Gram positive) and Escherichia coli ATCC 11229 (Gram negative) through disc diffusion technique (DDT). The characterization of functionalized zeolite NaY with fourier transform infrared (FTIR) spectroscopy indicated the attachment of APTES on zeolite NaY. Through DDT, the inhibition zone of functionalized zeolite NaY increased proportionally to the amount of the amine-functional group attached onto zeolite NaY. Functionalized zeolite NaY showed higher antibacterial activity against Gram-positive compared to Gram-negative bacteria. It can be concluded from this study that amine-functionalized zeolite NaY shows evidence of antibacterial activities.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Gaurav Rajauria ◽  
Nissreen Abu-Ghannam

Seaweeds are important sources of carotenoids, and numerous studies have shown the beneficial effects of these pigments on human health. In the present study,Himanthalia elongatabrown seaweed was extracted with a mixture of low polarity solvents, and the crude extract was separated using analytical thin-layer chromatography (TLC). The separated compounds were tested for their potential antioxidant capacity and antimicrobial activity againstListeria monocytogenesbacteria using TLC bioautography approach. For bio-autography, the coloured band on TLC chromatogram was visualized after spraying with DPPH and triphenyl-tetrazolium chloride reagents which screen antioxidant and antimicrobial compounds, respectively, and only one active compound was screened on the TLC plate. Preliminary identification of this active compound was done by comparing its colour andRf(retention factor) value with the authentic fucoxanthin standard. Further, the active compound was purified using preparative TLC. This purified compound showed a strong antioxidant (EC50:14.8±1.27 µg/mL) and antimicrobial (inhibition zone: 10.27 mm, 25 µg compound/disc) activities, which were examined by DPPH scavenging and agar disc-diffusion bioassay, respectively. The bioactivity shown by the purified compound was almost similar to the fucoxanthin standard. The characteristic UV-visible and FT-IR spectra of the purified active compound completely matched with the standard. Hence, the main active compound inH. elongatawas identified as fucoxanthin.


Copper (II) complex of naphthaldehyde thiosemicarbazone (L) has been synthesized and characterized by melting points, conductance, magnetic, infrared, and ESI-MS spectral measurements in addition to elemental analysis. A tetrahedral structure is suggested for the complex. The antibacterial activities of the complex and ligand were evaluated by the disc diffusion technique. Pure bacteria cultures of Bacillus subtilis (Gram-positive) and Escherichia coli (Gram-negative) were used to check the antibacterial activities of the synthesized compounds. Antibacterial activities were compared by measuring the inhibition zone diameter and chloramphenicol was used as a reference. Both the compounds showed significant antibacterial activity in different range against gram-positive & gram-negative bacteria. The antibacterial activity data also show that the Cu(II) complex to be more effective than the parent ligand. Molecular geometry of the complex has been optimized by ChemDraw Ultra 12.0 and then MM2 calculation has been done.


2019 ◽  
Vol 6 (3) ◽  
pp. 06-15
Author(s):  
David Timi ◽  
Subramaniyam Gopalakrishnan ◽  
Macquin Maino

Plant mediated green-synthesized silver nanoparticles (AgNPs) and the bioactivity on pathogenic micro-organisms is discussed. In the present investigation, aqueous leaf extracts of a medicinal plant, Ficus copiosa was utilized to construct AgNPs. The synthesized AgNPs was characterized by Ultraviolet-visible (UV-vis), Fourier Transform-infrared (FT-IR), X-ray Diffraction (XRD) spectrometer and Scanning Electron Microscopy (SEM) analysis. The phytosynthesized AgNPs exhibited comparable antimicrobial activity with two reference antibiotics against five indicator micro-organisms including two gram-positive (G+) bacteria, two gram-negative (G-) bacteria and a Protozoa (Pz). Study of the minimum inhibition concentration shows the two gram-negative bacteria to be more susceptible to AgNPs than the two gram-positive bacteria. The organisms included in the study are namely, B. Subtilis (G+), S. aureus (G+), E. coli (G-), S. pneumonia (G-) and T. vaginalis (Pz). Agar Disc diffusion technique was employed to assess the efficacy of the silver nanoparticles on the micro-organisms.


2020 ◽  
Vol 71 (9) ◽  
pp. 23-31
Author(s):  
Ileana Nichita ◽  
Lavinia Lupa ◽  
Radu Valentin Gros ◽  
Aurelia Visa ◽  
Adriana Popa ◽  
...  

Cellulose acetate (CA) is one of the most important esters of cellulose and it was analyzed by means of Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and EDX spectra. The FT-IR spectrum presented both the C=O and C�O stretching bands for acetyl groups. The EDX spectrum confirms the presence of C and O elements. The SEM image presented a spongy structure that is important for many applications. The antimicrobial properties of cellulose acetate solutions in acetic acid were determined in tests on two gram-negative species (Pseudomonas aeruginosa - ATCC 27853 and Escherichia coli - ATCC 25822), two gram-positive species (Staphylococus aureus - ATCC 29213 and Streptococcus pyogenes - ATCC 19615) and yeast species (Candida albicans - ATCC 10231). We have shown that samples of cellulose acetate solutions in acetic acid can be used to fight microbial and fungal infections. Of the gram-positive species tested, the strongest antimicrobial effect was observed against S. aureus. The diameter of inhibition zones of cellulose acetate solutions in acetic acid (P1 and P2) for S. aureus far exceeded inhibition zone both of reference substance (gentamicin) and of acetic acid solutions (M1 and M2), given values between 3.15 cm (P1) and 3.55 cm (P2). Also, the results suggested that the studied solutions (P1 and P2) had an antimicrobial effect pronounced for gram-negative species as P. aeruginosa, in which the P1 sample gave an inhibition zone of 2.95 cm, and the P2 sample achieved an inhibition of 3.15 cm. So, the antimicrobial activity of cellulose acetate solutions tested in vitro had a good antimicrobial effect, proportional to the concentration of the active substance.


Author(s):  
Elaf Ayad Kadhem ◽  
Miaad Hamzah Zghair ◽  
Sarah , Hussam H. Tizkam, Shoeb Alahmad Salih Mahdi ◽  
Hussam H. Tizkam ◽  
Shoeb Alahmad

magnesium oxide nanoparticles (MgO NPs) were prepared by simple wet chemical method using different calcination temperatures. The prepared NPs were characterized by Electrostatic Discharge (ESD), Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD). It demonstrates sharp intensive peak with the increase of crystallinty and increase of the size with varying morphologies with respect to increase of calcination temperature. Antibacterial studies were done on gram negative bacteria (E.coli) and gram positive bacteria (S.aureus) by agar disc diffusion method. The zones of inhibitions were found larger for gram positive bacteria than gram negative bacteria, this mean, antibacterial MgO NPs activity more active on gram positive bacteria than gram negative bacteria because of the structural differences. It was found that antibacterial activity of MgO NPs was found it has directly proportional with their concentration.


2020 ◽  
Vol 20 (1) ◽  
pp. 69-75
Author(s):  
Santi M. Mandal ◽  
Subhanil Chakraborty ◽  
Santanu Sahoo ◽  
Smritikona Pyne ◽  
Samaresh Ghosh ◽  
...  

Background: The need for suitable antibacterial agents effective against Multi-drug resistant Gram-negative bacteria is acknowledged globally. The present study was designed to evaluate the possible antibacterial potential of an extracted compound from edible flowers of Moringa oleifera. Methods: Five different solvents were used for preparing dried flower extracts. The most effective extract was subjected to fractionation and further isolation of the active compound with the highest antibacterial effect was obtained using TLC, Column Chromatography and reverse phase- HPLC. Approaches were made for characterization of the isolated compound using FTIR, NMR and Mass spectrometry. Antibacterial activity was evaluated according to the CLSI guidelines. Results: One fraction of aqueous acetic acid extract of M. oleifera flower was found highly effective and more potent than conventional antibiotics of different classes against Multi-drug resistant Gram-negative bacilli (MDR-GNB) when compared. The phytochemical analysis of the isolated compound revealed the presence of hydrogen-bonded amine and hydroxyl groups attributable to unsaturated amides. Conclusion: The present study provided data indicating a potential for use of the flowers extract of M. oleifera in the fight against infections caused by lethal MDR-GNB. Recommendations: Aqueous acetic acid flower extract of M. oleifera is effective, in-vitro, against Gram-negative bacilli. This finding may open a scope in pharmaceutics for the development of new classes of antibiotics.


Author(s):  
Andri Frediansyah ◽  
Jan Straetener ◽  
Heike Brötz-Oesterhelt ◽  
Harald Gross

AbstractA cyclic tetrapeptide, designated massiliamide, was isolated from the liquid culture of the Gram-negative bacterium Massilia albidiflava DSM 17472T. The structure was elucidated through extensive spectroscopic analysis, including HR-MS and 1D and 2D NMR experiments. The absolute configuration was determined using the Marfey´s method. Massiliamide showed potent inhibitory activity towards tyrosinase with an IC50 value of 1.15 µM and no cytotoxicity.


Molbank ◽  
10.3390/m1238 ◽  
2021 ◽  
Vol 2021 (2) ◽  
pp. M1238
Author(s):  
Ion Burcă ◽  
Valentin Badea ◽  
Calin Deleanu ◽  
Vasile-Nicolae Bercean

A new azo compound was prepared via the azo coupling reaction between 4-(ethoxycarbonyl)-3-methyl-1H-pyrazole-5-diazonium chloride and 8-hydroxyquinoline (oxine). The ester functional group of the obtained compound was hydrolyzed and thus a new chemical structure with a carboxylic functional group resulted. The structures of the new compounds were fully characterized by: UV–Vis, FT-IR, 1D and 2D NMR spectroscopy, and HRMS spectrometry.


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